TMC2130 sensorless homing; forces? November 14, 2018 02:21PM |
Registered: 7 years ago Posts: 162 |
Re: TMC2130 sensorless homing; forces? November 14, 2018 04:06PM |
Registered: 10 years ago Posts: 14,672 |
Re: TMC2130 sensorless homing; forces? November 18, 2018 10:44PM |
Registered: 10 years ago Posts: 564 |
Re: TMC2130 sensorless homing; forces? November 19, 2018 11:15AM |
Registered: 6 years ago Posts: 1,007 |
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LoboCNC
A more accurate way to use stall detection for Z axis homing is to lower the Z axis in small increments and then move the nozzle back & forth in the X (or Y) direction with a very low current setting and detect the X (or Y) motor stall as the nozzle drags on the bed. This is what the MOD-t printer did, although it used servo motors and encoders rather than open-loop stepper drivers with stall detection.
Re: TMC2130 sensorless homing; forces? November 19, 2018 12:39PM |
Registered: 10 years ago Posts: 564 |
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MKSA
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LoboCNC
A more accurate way to use stall detection for Z axis homing is to lower the Z axis in small increments and then move the nozzle back & forth in the X (or Y) direction with a very low current setting and detect the X (or Y) motor stall as the nozzle drags on the bed. This is what the MOD-t printer did, although it used servo motors and encoders rather than open-loop stepper drivers with stall detection.
Gee, all this in lieu of a simple microswitch ? The company went belly up BTW.
The OP is using steppers. See DC42 answer.
Re: TMC2130 sensorless homing; forces? November 20, 2018 02:13AM |
Registered: 6 years ago Posts: 1,007 |
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LoboCNC
With stepper motor stall detection, you can use the same basic technique as you can with servo motors. And yes, all to replace a microswitch (and its wiring and its offset adjustment). This technique actually has some advantages over a microswitch in that it is independent of bed thickness changes (switching cover glass, etc.) and it can also be used over different regions of the print bed to provide bed leveling information. (And I suspect New Matter didn't go out of business because of their Z-axis homing.)
Re: TMC2130 sensorless homing; forces? November 20, 2018 06:51AM |
Registered: 7 years ago Posts: 162 |
Re: TMC2130 sensorless homing; forces? November 20, 2018 07:38AM |
Registered: 6 years ago Posts: 1,007 |
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HugoW
What Z-sensor do you use, that measures / reacts to the force?
Thanks,
Hugo